Embedding is the opposite of extending. Rather that taking C code and wrapping it into Python, we take a large C code and embed a Python interpreter inside it. As mentioned in the text, this has the effect of giving a monolithic application the power of having an embedded Python interpreter. For example, apps that provide the functionality of running a Python interpreter (perhaps offline) on your iPhone essentially embed the Python interpreter in the phone system. Python interpreter can be required for a multitude of purposes - for rapid calculations, for example, which are otherwise difficult to express in other languages.